Much of the discussion so far has focused on what the implications of Fukushima are in the near term. I have been trying to read the tea leaves as to what the accident might mean for the longer term future of nuclear power--that is, after we have implemented any modifications to existing reactors and to reactors currently under construction or in the planning pipeline. I have written and spoken on this subject in several venues in the last few months. Most recently, an article I wrote for the ASME Mechanical Engineering journal on "Nuclear Power After Fukushima" was published. (I understand the link to the ASME website may not be maintained, so if clicking on the title fails to bring up the article, as an alternative, I have posted a PDF of the article on my personal website.)
While I have no reliable way to predict the future, I have seen repeated references to the fact that some of the more advanced designs now on the drawing board would not have been vulnerable to the main problems that plagued the Fukushima reactors. This has led me to believe that the accident could give additional impetus to what was already a growing interest in advanced reactor technologies and/or small modular reactor (SMR--also sometimes "small and medium reactor") designs.
Some of the characteristics that seem to be of particular relevance include the use of coolants other than water and the ability of some reactors to continue to be cooled by natural circulation. These two factors alone would make the long-term loss of cooling water and offsite power much less important, and could also allow siting away from tsunami--or flood--prone coastlines or river shorelines. (I mention non-water-cooled technologies only to illustrate a point, and note that there are water-cooled SMR design concepts that should also have less vulnerability to Fukushima-type events.)
On the other hand, of course, these reactors are still on the drawing board, and I am very mindful of Admiral Rickover's famous quote about paper reactors vs. real reactors. To paraphrase: a reactor (or, for that matter, any other complex technological device) that is still under development always looks perfect; it is when you start to build it that all the problems materialize. (But do look up the original quote--it's so much better!) Much more work remains to be done to demonstrate that the advanced reactors will perform as anticipated--and even more importantly, that we do not introduce new vulnerabilities. The Mechanical Engineering article discusses some of the issues in greater detail for those who are interested.
One interesting side note about the issue of the journal in which the article appears is that this is a special issue, and the topics for the articles in the issue were selected by "crowd sourcing." Using that process, the subject of advanced reactors was identified as one topic of reader interest. I was pleased to learn of that interest and to contribute my thoughts on the subject, and particularly on how the Fukushima events might shape the development of such designs.
With that, I'd like to wish everyone all the best for the New Year! See you back here next year!